From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 982B91F4FAC; Thu, 7 Nov 2024 11:27:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730978860; cv=none; b=koikzLzG/O9Ms5E0a7WLHfep6Ou26pHpPQHGE63Y06CONOV54bL2uq9FP1AhFDtrdUBq74g/LYEsFB7y1VkXkApARS6u21tm202dCGHeNoBc5v5zPphoigUbj2FItpUzw46HRXFg/ybV+c9sBDtrJ0mRK8cjgUCjlZwZ/mRF/Vs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730978860; c=relaxed/simple; bh=CiRRGlsT3dDhWyONtG/CZiwwSxcdju77JCm6fWfpbFE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mRe/oLd+5ynKTxWX8lKKDbPIBUGOLFnvap8TGuCQMekbovGMKQi6w15DZGFzG/nguDnVKpfetBMTthZwbov+kUL5I7OQ3ywKxIPZdCRiGNWE/2xzeUmeQUC4Q+e0kdbS2oNtWdAIQMsPGM/m6RldmzcBaBIsmGxakJZvV+KQ5hE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB575C4CECC; Thu, 7 Nov 2024 11:27:36 +0000 (UTC) Date: Thu, 7 Nov 2024 11:27:34 +0000 From: Manivannan Sadhasivam To: Chris Lew Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Hemant Kumar , Loic Poulain , Maxim Kochetkov , Manivannan Sadhasivam , Bjorn Andersson , linux-arm-msm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Bhaumik Bhatt , Johan Hovold Subject: Re: [PATCH] net: qrtr: mhi: synchronize qrtr and mhi preparation Message-ID: <20241107112734.v2ik6ipnebetjene@thinkpad> References: <20241104-qrtr_mhi-v1-1-79adf7e3bba5@quicinc.com> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20241104-qrtr_mhi-v1-1-79adf7e3bba5@quicinc.com> On Mon, Nov 04, 2024 at 05:29:37PM -0800, Chris Lew wrote: > From: Bhaumik Bhatt > > The call to qrtr_endpoint_register() was moved before > mhi_prepare_for_transfer_autoqueue() to prevent a case where a dl > callback can occur before the qrtr endpoint is registered. > > Now the reverse can happen where qrtr will try to send a packet > before the channels are prepared. Add a wait in the sending path to > ensure the channels are prepared before trying to do a ul transfer. > > Fixes: 68a838b84eff ("net: qrtr: start MHI channel after endpoit creation") > Reported-by: Johan Hovold > Closes: https://lore.kernel.org/linux-arm-msm/ZyTtVdkCCES0lkl4@hovoldconsulting.com/ > Signed-off-by: Bhaumik Bhatt > Signed-off-by: Chris Lew I think we need to have the check in 'mhi_queue()' instead of waiting for the channels in client drivers. Would it be a problem if qrtr returns -EAGAIN from qcom_mhi_qrtr_send() instead of waiting for the channel? - Mani > --- > net/qrtr/mhi.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c > index 69f53625a049..5b7268868bbd 100644 > --- a/net/qrtr/mhi.c > +++ b/net/qrtr/mhi.c > @@ -15,6 +15,7 @@ struct qrtr_mhi_dev { > struct qrtr_endpoint ep; > struct mhi_device *mhi_dev; > struct device *dev; > + struct completion prepared; > }; > > /* From MHI to QRTR */ > @@ -53,6 +54,10 @@ static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb) > if (skb->sk) > sock_hold(skb->sk); > > + rc = wait_for_completion_interruptible(&qdev->prepared); > + if (rc) > + goto free_skb; > + > rc = skb_linearize(skb); > if (rc) > goto free_skb; > @@ -85,6 +90,7 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, > qdev->mhi_dev = mhi_dev; > qdev->dev = &mhi_dev->dev; > qdev->ep.xmit = qcom_mhi_qrtr_send; > + init_completion(&qdev->prepared); > > dev_set_drvdata(&mhi_dev->dev, qdev); > rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO); > @@ -97,6 +103,7 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, > qrtr_endpoint_unregister(&qdev->ep); > return rc; > } > + complete_all(&qdev->prepared); > > dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n"); > > > --- > base-commit: 1ffec08567f426a1c593e038cadc61bdc38cb467 > change-id: 20241104-qrtr_mhi-dfec353030af > > Best regards, > -- > Chris Lew > -- மணிவண்ணன் சதாசிவம்